Attentional control refers to an individual's ability to selectively attend to behaviorally relevant stimuli and ignore behaviorally irrelevant stimuli. There are at least two separable components to attentional control, shifting and monitoring, which are each driven by different neural networks in the mammalian prefrontal cortex. During normative aging, both the shifting and monitoring components of attention are impaired in humans, and these alterations negatively impact life quality since the execution of many basic skills is dependent on these mental processes. The neural network level changes that lead to impaired attentional control are poorly understood. This is in part due to the current lack of animal models that can provide neural data with superior spatial and temporal resolution to clarify the functional imaging and EEG data available in humans. Recently, our laboratory has shown that aged macaque monkeys experience performance deficits on tasks requiring attentional control in a manner similar to that which is noted in older humans. The experiments proposed here test the hypothesis that networks of inhibitory neurons in the dorsolateral prefrontal cortex of macaques are altered during normative aging to give rise to declines in attentional control. Chronic extracellular tetrode recording devices and novel behavioral paradigms will be used to track covariation in behavior and underlying neural responses in the non-human primate. The results from these studies have the potential to identify specific cellular components impacted by aging that give rise to declines in attentional control, a hallmark of cognitive aging in humans.
This research will enable a better understanding of how networks critical for cognition are altered during the aging process. Experiments are designed to determine why older individuals are more susceptible to interference when attentional shifting and monitoring are required. This knowledge will be used to test possible treatments that target points of known circuit dysfunction in order to optimize cognitive healthspan in the elderly.